Esurance offers a cellphone blocker

Esurance now offers parents a way to block teen drivers’ access to text messages, email, phone calls and other distractions while a car is moving.

While a number of mobile phone companies offer free or discounted technology to stop cellphone use while behind the wheel (See “Please make me stop texting.”), Esurance says it is the first major car insurance company to do so.

Esurance customers download the Cellcontrol app and then plug a device into the onboard diagnostics (OBD) port of their vehicle. The system uses non-pairing Bluetooth technology, which engages the device when the vehicle starts moving, prohibiting forbidden functions. Once the car stops, full functionality is restored to the phone.

The Cellcontrol app blocks mobile phone calls, Internet usage, texting and other distracting applications while the car is moving.

Keeping teens focused on the road is a top priority not only for parents but safety officials. Traffic accidents are still the leading killer of teens and the latest stats on distracted driving show distractions killed 3,331 people in 2011. Recent reports show teen deaths on the rise after eight years of decline.

Many states have begun ramping up the penalties for drivers who text -- for example, making texting a moving violation that appears on driving records and increases insurance rates. We think that's a great step -- but preventing the behavior in the first place is even better.

Chuck Cox, senior vice president at Cellcontrol, says a blocking screen pops up if an unauthorized activity is attempted. Allowed and disallowed functions can be customized and managed by parents on a Web-based dashboard.

In addition to blocking distracting activities, the app also provides parents with information about how their teen is driving, monitoring speed, mileage, hard braking, quick acceleration and other factors.

Speed thresholds can be set and an instant alert sent to the parents whenever the threshold is exceeded. Cox tells of one customer who received an alert that his car was currently going 91 mph. That teen driver lost the keys to the family car for a while. (See "7 Ways to spy on your teen driver.")

Cellcontrol works with the latest Blackberry, Android and the majority of Windows phones but is not yet available on the iPhone.